[GROOVY-6989] .each{..} Closure With Parameter Typed As Object[] Makes Arguments Object[Object[]]

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 2.3.3, 2.4.0-beta-1, 2.3.4, 2.3.5, 2.3.6
• Fix Version/s: 2.4.0-beta-4
• Labels: breaking
• Environment: Windows 7 x64 SP1 on JVM 1.7.0_17
• Assignee: Jochen Theodorou
• Reporter: Alex Beardsley
• Created: 30/Jul/14 12:45
• Updated: 15/Jan/15 07:57
• Resolved: 22/Oct/14 09:51

Description

When iterating over a List of Object[] in a .each closure and typing the parameter as Object[], the arguments in each iteration become an Object[] of Object[]. This does not happen if the parameter is def.

Object[] arr = new Object[1]
arr[0] = 'test'
List list = new ArrayList()
list.add(arr)

list.each { def obj ->
    assert obj[0] == 'test'
}

list.each { Object[] obj ->
    assert obj[0] == 'test' //fails. obj[0] is Object[]{'test'} instead of just 'test'
}

This does not happen if the parameter is typed as String[]:

String[] arr = new String[1]
arr[0] = 'test'
List list = new ArrayList()
list.add(arr)

list.each { def obj ->
    assert obj[0] == 'test'
}

list.each { String[] obj ->
    assert obj[0] == 'test' // passes
}

I have included a more thorough test case that demonstrates this behavior. Note that this may also apply to .collect or various other methods.

Issue Links

• relates to: GROOVY-7254 Problem With Null Parameter To Meta Method